This invention relates to drug delivery devices and, more particularly, to needle-mounting adaptors for drug delivery devices.
Medical pen injectors are well known in the prior art. Pen injectors may have a continuous solid body which houses a cartridge of drug to be administered. This is typically used for single-use pen injectors, where, once a drug cartridge is exhausted, the pen injector is intended for disposal. Re-useable pen injectors are known in the art, such as that shown in U.S. Pat. No. 5,931,817, which is incorporated by reference herein in its entirety. As shown in U.S. Pat. No. 5,931,817, a pen injector may be provided which includes a removable cartridge retainer which can be repeatedly removed to allow for use with multiple drug cartridges. In any regard, drug cartridges are accommodated by pen injectors and are formed to standard sizes, as dictated by ISO specifications (e.g., ISO 11608-3). Thus, with a drug cartridge formed to dimensions outside of the ISO specifications, it may not be accommodated by a standard pen injector.
A need has been developed in the prior art to accommodate a drug cartridge with a larger front end. The front end may be dimensioned so as to be larger than the body of a drug delivery device, such as a medical pen injector, thus preventing full insertion thereinto. A larger front end may be desired to accommodate larger drug volumes or for other considerations, such as manufacturing considerations. A larger front end may permit easier filling, particularly of a powdered or granular substance. With a larger front end, the drug cartridge may extend externally from the body of the drug delivery device. As such, a pen needle can not be mounted onto the body as is known in the prior art.